Abstract Axonal degeneration significantly contributes to functional loss after spinal cord injury (SCI). Grafting neural progenitors derived from patients? own induced pluripotent stem cells (iPSCs) is a promising strategy to establish neuronal relay for reconnecting injured long tracts with their denervated neurons and promoting functional recovery. We hypothesize that co-transplanted human iPSC-derived glial restricted progenitors (GRPs) and neuronal restricted progenitors (NRPs) will work synergistically to form neuronal relays for the injured tracts and that multineurotrophin D15A will direct grafted neurons to form functional synapses with denervated target neurons and promote greater functional recovery in both laceration and contusion cervical SCI animal models. In this proposal, we will test (1) if co-transplanted human iPSC-derived GRPs and NRPs will work synergistically to form neuronal relays for the injured ascending dorsal column tract (DCT) and descending corticospinal tract (CST), and promote functional recovery after C3 dorsal funiculus laceration; (2) if gradient multineurotrophin D15A in dorsal nuclei and caudal ventral horn will direct grafted neurons to extend axons toward and form functional synapses with denervated target neurons of DCT and CST, and promote greater functional recovery; and (3) if grafted NRPs and GRPs will integrate into the spared circuits and promote functional recovery after clinically relevant cervical contusion SCI. Data obtained from the proposed approach will be critical in developing safe and effective patient-specific iPSC-based restorative therapies for SCI in the near future.